Re: [GIT PATCH] SCSI bug fixes for 2.6.24-rc3

[FUJITA Tomonori <tomof@acm.org>]

CC'ed Jes,

On Tue, 8 Jan 2008 14:15:53 +0300
Evgeniy Dushistov <dushistov@mail.ru> wrote:

> On Sun, Nov 25, 2007 at 01:24:25PM +0200, James Bottomley wrote:
> > This is a bit of a rash of bug fixes.  The qla1280 is actually a bug fix
> > (in spite of the title---it's actually correcting an existing problem
> > with the qla1280 implementation of accessors that broke the current
> > driver).
> > 
> 
> Recently I build last Linus's git tree, and got:
> req_cnt is used uninitialized in this function,
> and see bellow
> > The patch is available here:
> > 
> > master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6.git
> > 
> > The short changelog is:
> ...
> > Jes Sorensen (1):
> >       qla1280: convert to use the data buffer accessors
> > 
> ...
> >  scsi/qla1280.c         |  387 +++++++++++++++++++++----------------------------
> ...
> >  	/* Calculate number of entries and segments required. */
> > -	req_cnt = 1;
> > 
> 
> Initilization of req_cnt was removed, but in this function
> there are places like 
> req_cnt += (seg_cnt - 4) / 7;
> or
> req_cnt++;
> This is should be so?

req_cnt should not be removed. Jes tested the patch but this critical
bug appears only with BITS_PER_LONG != 64 && CONFIG_HIGHMEM=n case. So
he didn't see this, I think.

qla1280_32bit_start_scsi also gives the following warning:

drivers/scsi/qla1280.c: In function 'qla1280_32bit_start_scsi':
drivers/scsi/qla1280.c:3044: warning: unused variable 'dma_handle'


diff --git a/drivers/scsi/qla1280.c b/drivers/scsi/qla1280.c
index 146d540..2886407 100644
--- a/drivers/scsi/qla1280.c
+++ b/drivers/scsi/qla1280.c
@@ -3041,7 +3041,6 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
 	int cnt;
 	int req_cnt;
 	int seg_cnt;
-	dma_addr_t dma_handle;
 	u8 dir;
 
 	ENTER("qla1280_32bit_start_scsi");
@@ -3050,6 +3049,7 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
 		cmd->cmnd[0]);
 
 	/* Calculate number of entries and segments required. */
+	req_cnt = 1;
 	seg_cnt = scsi_dma_map(cmd);
 	if (seg_cnt) {
 		/*